/*******************************************************************************
 * Copyright (c) 2006, 2010 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 * Contributors:
 * IBM Corporation - initial API and implementation
 *******************************************************************************/

package cn.elwy.rcp.ui.navigator.internal.resources.actions;

import org.eclipse.jface.action.Action;
import org.eclipse.jface.action.ContributionItem;
import org.eclipse.jface.action.IAction;
import org.eclipse.jface.action.IMenuManager;
import org.eclipse.jface.action.MenuManager;
import org.eclipse.jface.action.Separator;
import org.eclipse.jface.viewers.StructuredViewer;
import org.eclipse.swt.SWT;
import org.eclipse.swt.events.SelectionAdapter;
import org.eclipse.swt.events.SelectionEvent;
import org.eclipse.swt.widgets.Menu;
import org.eclipse.swt.widgets.MenuItem;
import org.eclipse.ui.IActionBars;
import org.eclipse.ui.ISharedImages;
import org.eclipse.ui.IWorkbenchActionConstants;
import org.eclipse.ui.PlatformUI;
import org.eclipse.ui.actions.ActionGroup;
import org.eclipse.ui.ide.IDE;
import org.eclipse.ui.navigator.IExtensionStateModel;

import cn.elwy.rcp.ui.navigator.internal.resources.plugin.WorkbenchNavigatorMessages;
import cn.elwy.rcp.ui.navigator.internal.resources.plugin.WorkbenchNavigatorPlugin;
import cn.elwy.rcp.ui.navigator.internal.workingsets.WorkingSetsContentProvider;

/**
 * Provides the radio buttons at the top of the view menu that control the root of the ProjectExplorer, which is either
 * working sets of projects. When the state is changed through the actions, the
 * WorkingSetsContentProvider.SHOW_TOP_LEVEL_WORKING_SETS property in the extension state model is updated. This is
 * installed by the WorkingSetActionProvider.
 * 
 * @since 3.2
 */
public class WorkingSetRootModeActionGroup extends ActionGroup {

  private IExtensionStateModel stateModel;
  private StructuredViewer structuredViewer;

  private boolean hasContributedToViewMenu = false;
  private IAction workingSetsAction = null;
  private IAction projectsAction = null;
  private IAction[] actions;
  private int currentSelection;
  private MenuItem[] items;

  private class TopLevelContentAction extends Action {

    private final boolean groupWorkingSets;

    /**
     * Construct an Action that represents a toggle-able state between Showing top level Working Sets and Projects.
     * 
     * @param toGroupWorkingSets
     */
    public TopLevelContentAction(boolean toGroupWorkingSets) {
      super("", AS_RADIO_BUTTON); //$NON-NLS-1$
      groupWorkingSets = toGroupWorkingSets;
    }

    /*
     * @see org.eclipse.jface.action.IAction#run()
     */
    public void run() {
      if (stateModel.getBooleanProperty(WorkingSetsContentProvider.SHOW_TOP_LEVEL_WORKING_SETS) != groupWorkingSets) {
        stateModel.setBooleanProperty(WorkingSetsContentProvider.SHOW_TOP_LEVEL_WORKING_SETS, groupWorkingSets);

        structuredViewer.getControl().setRedraw(false);
        try {
          structuredViewer.refresh();
        } finally {
          structuredViewer.getControl().setRedraw(true);
        }
      }
    }
  }

  /**
   * Create an action group that will listen to the stateModel and update the structuredViewer when necessary.
   * 
   * @param aStructuredViewer
   * @param aStateModel
   */
  public WorkingSetRootModeActionGroup(StructuredViewer aStructuredViewer, IExtensionStateModel aStateModel) {
    super();
    structuredViewer = aStructuredViewer;
    stateModel = aStateModel;
  }

  /*
   * (non-Javadoc)
   * @see ActionGroup#fillActionBars(IActionBars)
   */
  public void fillActionBars(IActionBars actionBars) {
    if (hasContributedToViewMenu)
      return;
    IMenuManager topLevelSubMenu = new MenuManager(
        WorkbenchNavigatorMessages.WorkingSetRootModeActionGroup_Top_Level_Element_);
    addActions(topLevelSubMenu);
    actionBars.getMenuManager().insertBefore(IWorkbenchActionConstants.MB_ADDITIONS, topLevelSubMenu);
    hasContributedToViewMenu = true;
  }

  /**
   * Adds the actions to the given menu manager.
   */
  protected void addActions(IMenuManager viewMenu) {
    if (actions == null)
      actions = createActions();

    viewMenu.add(new Separator());
    items = new MenuItem[actions.length];

    for (int i = 0; i < actions.length; i++) {
      final int j = i;

      viewMenu.add(new ContributionItem() {

        public void fill(Menu menu, int index) {

          int style = SWT.CHECK;
          if ((actions[j].getStyle() & IAction.AS_RADIO_BUTTON) != 0)
            style = SWT.RADIO;

          final MenuItem mi = new MenuItem(menu, style, index);
          items[j] = mi;
          mi.setText(actions[j].getText());
          mi.setSelection(currentSelection == j);
          mi.addSelectionListener(new SelectionAdapter() {

            public void widgetSelected(SelectionEvent e) {
              if (currentSelection == j) {
                items[currentSelection].setSelection(true);
                return;
              }
              actions[j].run();

              // Update checked state
              items[currentSelection].setSelection(false);
              currentSelection = j;
              items[currentSelection].setSelection(true);
            }

          });

        }

        public boolean isDynamic() {
          return false;
        }
      });
    }
  }

  private IAction[] createActions() {

    ISharedImages sharedImages = PlatformUI.getWorkbench().getSharedImages();

    projectsAction = new TopLevelContentAction(false);
    projectsAction.setText(WorkbenchNavigatorMessages.WorkingSetRootModeActionGroup_Project_);
    projectsAction.setImageDescriptor(sharedImages.getImageDescriptor(IDE.SharedImages.IMG_OBJ_PROJECT));

    workingSetsAction = new TopLevelContentAction(true);
    workingSetsAction.setText(WorkbenchNavigatorMessages.WorkingSetRootModeActionGroup_Working_Set_);
    workingSetsAction.setImageDescriptor(WorkbenchNavigatorPlugin.getDefault().getImageRegistry()
        .getDescriptor("full/obj16/workingsets.gif")); //$NON-NLS-1$

    return new IAction[] { projectsAction, workingSetsAction };
  }

  /**
   * Toggle whether top level working sets should be displayed as a group or collapse to just show their contents.
   * 
   * @param showTopLevelWorkingSets
   */
  public void setShowTopLevelWorkingSets(boolean showTopLevelWorkingSets) {
    if (actions == null)
      actions = createActions();

    currentSelection = showTopLevelWorkingSets ? 1 : 0;
    workingSetsAction.setChecked(showTopLevelWorkingSets);
    projectsAction.setChecked(!showTopLevelWorkingSets);

    if (items != null) {
      for (int i = 0; i < items.length; i++) {
        if (items[i] != null && actions[i] != null)
          items[i].setSelection(actions[i].isChecked());
      }
    }
    if (stateModel != null) {
      stateModel.setBooleanProperty(WorkingSetsContentProvider.SHOW_TOP_LEVEL_WORKING_SETS, showTopLevelWorkingSets);
    }
  }

  /**
   * @param sStateModel
   */
  public void setStateModel(IExtensionStateModel sStateModel) {
    stateModel = sStateModel;
  }
}
